base64 – nocin.eu

[nodejs] base64 to buffer and vice versa

March 6, 2022 March 6, 2022

const myBase64File = "JVBERi0xLjQKJcOkw7zDtsOfCjIgMCBvYmoKPDwvTGVuZ3....."

const buffer = Buffer.from(myBase64File, "base64")
const base64 = buffer.toString("base64")

JavaScript / nodejs

[JavaScript] Download base64 encoded file within a browser

January 13, 2022 July 21, 2022

            const sBase64 = "JVBERi0xLjQKJcOkw7zDtsOfCjIgMCBvYmoKPDwvTGVuZ3....."
            const arrayBuffer = new Uint8Array([...window.atob(sBase64)].map(char => char.charCodeAt(0)))
            const fileLink = document.createElement('a')

            fileLink.href = window.URL.createObjectURL(new Blob([arrayBuffer]))
            fileLink.setAttribute('download', "example.pdf")
            document.body.appendChild(fileLink)
            fileLink.click()

Or use the npm package FileSaver.

import { saveAs } from "file-saver";

const sBase64 = "JVBERi0xLjQKJcOkw7zDtsOfCjIgMCBvYmoKPDwvTGVuZ3....."
const buffer = Buffer.from(sBase64, "base64") //Buffer is only available when using nodejs
saveAs(new Blob([buffer]), "example.pdf")

JavaScript / nodejs

[Postman] Visualize base64 image

November 23, 2021 November 23, 2021

If you have a service which returns a payload like the following (including a base64 endcoded jpeg) you can view it directly in postman.

{
        "photo": "/9j/4AAQSkZJRgABAgAAAQABAAD/2wBDAAMCAgMCAgMDAwMEAwMEBQgFBQQEBQoHBwYIDAoMDAsK\r\nCwsND..............",
        "photoId": "192",
        "mimeType": "image/jpeg"
}

This can be done with a few lines of code. In Postman navigate to the “Tests” tab:

and insert the following lines:

//output to postman console
console.log("PhotoId: " + pm.response.json()["photoId"]);
console.log("Base64: " + pm.response.json()["photo"]);

//output in visualize tab
let template = `<img src='{{img}}'/>`;

pm.visualizer.set(template, { 
    img: `data:image/jpeg;base64,${pm.response.json()["photo"]}`
});

In the “Visualize” tab you should now find your image